From owner-freebsd-hackers@FreeBSD.ORG Sun Jun 8 05:51:43 2008 Return-Path: Delivered-To: hackers@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 9BDDA1065672 for ; Sun, 8 Jun 2008 05:51:43 +0000 (UTC) (envelope-from kostikbel@gmail.com) Received: from mail.zoral.com.ua (skuns.zoral.com.ua [91.193.166.194]) by mx1.freebsd.org (Postfix) with ESMTP id 2465D8FC20 for ; Sun, 8 Jun 2008 05:51:42 +0000 (UTC) (envelope-from kostikbel@gmail.com) Received: from deviant.kiev.zoral.com.ua (root@deviant.kiev.zoral.com.ua [10.1.1.148]) by mail.zoral.com.ua (8.14.2/8.14.2) with ESMTP id m585pabF010079 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO); Sun, 8 Jun 2008 08:51:36 +0300 (EEST) (envelope-from kostikbel@gmail.com) Received: from deviant.kiev.zoral.com.ua (kostik@localhost [127.0.0.1]) by deviant.kiev.zoral.com.ua (8.14.2/8.14.2) with ESMTP id m585pa8n087504; Sun, 8 Jun 2008 08:51:36 +0300 (EEST) (envelope-from kostikbel@gmail.com) Received: (from kostik@localhost) by deviant.kiev.zoral.com.ua (8.14.2/8.14.2/Submit) id m585paSv087497; Sun, 8 Jun 2008 08:51:36 +0300 (EEST) (envelope-from kostikbel@gmail.com) X-Authentication-Warning: deviant.kiev.zoral.com.ua: kostik set sender to kostikbel@gmail.com using -f Date: Sun, 8 Jun 2008 08:51:36 +0300 From: Kostik Belousov To: Alan Cox Message-ID: <20080608055136.GT94309@deviant.kiev.zoral.com.ua> References: <484B20E7.2040009@cs.rice.edu> <20080608052653.GS94309@deviant.kiev.zoral.com.ua> <484B709F.1070503@cs.rice.edu> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="D5tFrmRBv7YOLFOK" Content-Disposition: inline In-Reply-To: <484B709F.1070503@cs.rice.edu> User-Agent: Mutt/1.4.2.3i X-Virus-Scanned: ClamAV version 0.91.2, clamav-milter version 0.91.2 on skuns.kiev.zoral.com.ua X-Virus-Status: Clean X-Spam-Status: No, score=-4.4 required=5.0 tests=ALL_TRUSTED,AWL,BAYES_00 autolearn=ham version=3.2.4 X-Spam-Checker-Version: SpamAssassin 3.2.4 (2008-01-01) on skuns.kiev.zoral.com.ua Cc: hackers@freebsd.org Subject: Re: Increasing KVM on amd64 X-BeenThere: freebsd-hackers@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Technical Discussions relating to FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 08 Jun 2008 05:51:43 -0000 --D5tFrmRBv7YOLFOK Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Sun, Jun 08, 2008 at 12:39:43AM -0500, Alan Cox wrote: > Kostik Belousov wrote: >=20 > >On Sat, Jun 07, 2008 at 06:59:35PM -0500, Alan Cox wrote: > >=20 > > > >>You can download a patch from=20 > >>http://www.cs.rice.edu/~alc/amd64_kvm_6GB.patch that increases amd64's= =20 > >>kernel virtual address space to 6GB. This patch also increases the=20 > >>default for the kmem map to almost 2GB. I believe that kernel loadable= =20 > >>modules still work. However, I suspect that mini-dumps are broken. > >> =20 > >> > >The amd64 modules text/data/bss virtual addresses are allocated from the= =20 > >kernel_map (link_elf_obj.c, link_elf_load_file). Now, the lower end > >of the kernel_map is top-6Gb. > > > >Kernel code (both kernel proper and modules) is compiled for "kernel mem= ory > >model", according to the gcc info: > >`-mcmodel=3Dkernel' > >Generate code for the kernel code model. The kernel runs in the > >negative 2 GB of the address space. This model has to be used for > >Linux kernel code. > > > >I suspect we have a problem there. > > > >=20 > > >=20 > The change to link_elf_obj.c is supposed to ensure allocation of an=20 > address in the upper 2GB of the kernel map for the module. Ah, I overlooked it, sorry. --D5tFrmRBv7YOLFOK Content-Type: application/pgp-signature Content-Disposition: inline -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.9 (FreeBSD) iEYEARECAAYFAkhLc2cACgkQC3+MBN1Mb4gNZQCgwQvQcQtvW/sIzRZ6aoFybfQS A3cAn1x0joGdGbEwq7mRBCbCTizeED1h =t2MU -----END PGP SIGNATURE----- --D5tFrmRBv7YOLFOK--